Subterranean deposits of coal (typically referred to as “coal seams”) often contain substantial quantities of entrained methane gas. Limited production and use of methane gas from coal seams has occurred for many years because substantial obstacles have frustrated extensive development and use of methane gas deposits in coal seams.
One system of obtaining methane gas from coal seams is to drill lateral wellbores into the coal seams. This is typically accomplished by a drill bit at the end of a drill string that is disposed within a casing string having a deflecting member at the lower end thereof. The deflecting member, sometimes referred to as a “whipstock,” directs the drill bit such that a lateral wellbore may be drilled in the coal seam.